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bb2109e7 | 1 | /* |
ad787160 C |
2 | * Copyright (c) 1988, 1989, 1990, 1993 |
3 | * The Regents of the University of California. All rights reserved. | |
c65fedcf | 4 | * |
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5 | * This code is derived from software contributed to Berkeley by |
6 | * Adam de Boor. | |
c65fedcf | 7 | * |
ad787160 C |
8 | * Redistribution and use in source and binary forms, with or without |
9 | * modification, are permitted provided that the following conditions | |
10 | * are met: | |
11 | * 1. Redistributions of source code must retain the above copyright | |
12 | * notice, this list of conditions and the following disclaimer. | |
13 | * 2. Redistributions in binary form must reproduce the above copyright | |
14 | * notice, this list of conditions and the following disclaimer in the | |
15 | * documentation and/or other materials provided with the distribution. | |
16 | * 3. All advertising materials mentioning features or use of this software | |
17 | * must display the following acknowledgement: | |
18 | * This product includes software developed by the University of | |
19 | * California, Berkeley and its contributors. | |
20 | * 4. Neither the name of the University nor the names of its contributors | |
21 | * may be used to endorse or promote products derived from this software | |
22 | * without specific prior written permission. | |
23 | * | |
24 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
25 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
26 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
27 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
28 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
29 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
30 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
31 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
32 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
33 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
34 | * SUCH DAMAGE. | |
c65fedcf | 35 | */ |
bb2109e7 | 36 | |
c65fedcf | 37 | #ifndef lint |
ad787160 | 38 | static char sccsid[] = "@(#)lstInsert.c 8.1 (Berkeley) 6/6/93"; |
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39 | #endif /* not lint */ |
40 | ||
41 | /*- | |
42 | * LstInsert.c -- | |
43 | * Insert a new datum before an old one | |
44 | */ | |
c65fedcf KB |
45 | |
46 | #include "lstInt.h" | |
47 | ||
48 | /*- | |
49 | *----------------------------------------------------------------------- | |
50 | * Lst_Insert -- | |
51 | * Insert a new node with the given piece of data before the given | |
52 | * node in the given list. | |
53 | * | |
54 | * Results: | |
55 | * SUCCESS or FAILURE. | |
56 | * | |
57 | * Side Effects: | |
58 | * the firstPtr field will be changed if ln is the first node in the | |
59 | * list. | |
60 | * | |
61 | *----------------------------------------------------------------------- | |
62 | */ | |
63 | ReturnStatus | |
64 | Lst_Insert (l, ln, d) | |
65 | Lst l; /* list to manipulate */ | |
66 | LstNode ln; /* node before which to insert d */ | |
67 | ClientData d; /* datum to be inserted */ | |
68 | { | |
69 | register ListNode nLNode; /* new lnode for d */ | |
70 | register ListNode lNode = (ListNode)ln; | |
71 | register List list = (List)l; | |
72 | ||
73 | ||
74 | /* | |
75 | * check validity of arguments | |
76 | */ | |
77 | if (LstValid (l) && (LstIsEmpty (l) && ln == NILLNODE)) | |
78 | goto ok; | |
79 | ||
80 | if (!LstValid (l) || LstIsEmpty (l) || !LstNodeValid (ln, l)) { | |
81 | return (FAILURE); | |
82 | } | |
83 | ||
84 | ok: | |
85 | PAlloc (nLNode, ListNode); | |
86 | ||
87 | nLNode->datum = d; | |
88 | nLNode->useCount = nLNode->flags = 0; | |
89 | ||
90 | if (ln == NILLNODE) { | |
91 | if (list->isCirc) { | |
92 | nLNode->prevPtr = nLNode->nextPtr = nLNode; | |
93 | } else { | |
94 | nLNode->prevPtr = nLNode->nextPtr = NilListNode; | |
95 | } | |
96 | list->firstPtr = list->lastPtr = nLNode; | |
97 | } else { | |
98 | nLNode->prevPtr = lNode->prevPtr; | |
99 | nLNode->nextPtr = lNode; | |
100 | ||
101 | if (nLNode->prevPtr != NilListNode) { | |
102 | nLNode->prevPtr->nextPtr = nLNode; | |
103 | } | |
104 | lNode->prevPtr = nLNode; | |
105 | ||
106 | if (lNode == list->firstPtr) { | |
107 | list->firstPtr = nLNode; | |
108 | } | |
109 | } | |
110 | ||
111 | return (SUCCESS); | |
112 | } | |
113 |